The field of the invention relates generally to probe assemblies and, more particularly, to a probe tip for use with a probe assembly, such as a probe assembly used in systems that perform phase shift analysis.
At least some known machines include at least one component that may become damaged or worn over time. For example, aircraft engines and/or power turbines may include components such as, bearings, gears, and/or rotor blades that wear over time. Continued operation with a worn component may cause additional damage to other components or may lead to a premature failure of the component and/or associated machine.
To detect component damage within machines, the operation of at least some known machines is inspected with an inspection system. Known inspection systems may include borescopes or endoscopes, which may include probes or probe assemblies, used to detect defects and/or to identify the magnitude of a defect within a component. Most probe assemblies may be inserted inside a remote cavity to detect the defect. Probe assemblies also include an external light source, such as, for example, fiber optic bundles or light emitters that are contained within the probe assembly to provide illumination of a remote component or surface of the component. When the component is illuminated, an internal image may be formed on an image sensor via a lens system. The image may then be relayed to a connected display system such that a user may be provided with a visual output and any defects may be readily identified by the user.
The image shown on the connected display system may vary in magnification and size depending on, for example, the distance between the object and a distal end of the probe with the lens system and the image sensor. Such variations may make it difficult to determine dimensional measurements, especially in three spatial dimensions. There are known approaches for providing three dimensional (3D) data through a probe. However, there are limitations in such approaches. For example, stereo methods may be used to create 3D view, but may only provide information where two points on an image can be correlated. The correlation process may also require significant processing. Accordingly, producing a full 3D surface map may be time consuming.
Phase-shifting may be used to obtain full-field object data. Phase-shifting generally involves projecting one or more sets of parallel lines that cross the field of view (FOV) of a camera. As the object distance changes, the parallel lines, or fringe sets, shift across the FOV. Phase-shifting methods may require the use of equipments, such as, for example, projectors and/or scanners, that may not mechanically fit within probes, such as borescopes and endoscopes. In order to overcome such size limitations, some known probe systems and assemblies have been configured to perform measurements and 3D surface mapping based on phase-shift analysis without the use of such large equipment. For example, such probe assemblies may include a plurality of light emitters that includes at least one emitter group. A pattern that is projected when one of the emitter groups is emitting includes a fringe set. Probe systems or assemblies may also include an imager for obtaining at least one image of a surface and a processing unit that performs phase-shift analysis on the image.
Each light emitter included within probe assemblies with phase-shifting capabilities may be coupled directly to a drive circuit via at least one wire and each wire may be selectively coupled together via a contact. For example, if such a probe assembly includes six light emitters, then six separate wires may be coupled to the drive circuit and each wire may include a contact coupled to it. As such, such a probe assembly would include at least six wires and six contacts. However, such probe assemblies may have diameters that are relatively small, i.e., between approximately 3.9 mm to 6.2 mm. As a result, such probe assemblies may have very little space for an increased number of wires and/or contacts for use with each of the light emitters. Accordingly, the number of light emitters that may be used within probe assemblies may be limited and, subsequently, the measurement capabilities of the probe assembly may be limited.